April in South Milwaukee is the rainiest month of the year. In April, the weather in South Milwaukee is typically warm. Average daily high temperature in April is about 10 degrees above zero. On average, South Milwaukee has 15 rainy, 6 sunny, 5 cloudy, and 4 partly cloudy days in April. The rains are usually heavy. April as well as March, May, and November is considered the most uncomfortable time to visit South Milwaukee.